Title

PACAP peptides modulate guinea pig cardiac neuron membrane excitability and neuropeptide expression

Document Type

Conference Proceeding

Publication Date

1-1-2000

Abstract

Morphological studies identified PACAP-immunoreactive nerve fibers in dense pericellular arrangements around virtually every cholinergic parasympathetic neuron of guinea pig cardiac ganglia; all postganglionic cardiac neurons expressed membrane-associated PAC receptor protein. Characterization of the alternative splice variants established predominant expression of the PAC (very short) receptor transcript containing neither HIP nor HOP exons. PACAP depolarized cardiac neurons and increased membrane excitability; the excitability resulted from neither altered action potential properties nor inhibition of I . Treatment of cardiac ganglia explants with PACAP significantly reduced the numbers of cholinergic neurons coexpressing somatostatin immunoreactivity, which did not appear to be correlated with prosomatostatin mRNA expression. The PACAP-mediated decrease in somatostatin immunoreactive neurons required calcium influx through L-type calcium channels and activation of adenylyl cyclase, whereas activation of phospholipase C or protein kinase A was not required. These observations indicate that PACAP through the PAC receptors elicits complex actions on guinea pig parasympathetic cardiac ganglia neurons, including modulation of membrane ion conductances and modulation of neuropeptide expression. 1 1 M 1

Publication Name

Annals of the New York Academy of Sciences

Volume Number

921

First Page

202

Last Page

210

DOI

10.1111/j.1749-6632.2000.tb06967.x

This document is currently not available here.

Share

COinS